Brake shoe



Aug. 9, 1960 C. R. LUPTON BRAKE SHOE Original Filed Feb. 21,

INVENTOR.

624/0406? ZZ/P/dA/ v ATTORNEY States Aviation Corporation, South Bend,Ind., a corporation of Delaware Continuation of abandoned applicationSer. No. 145,365, Feb. 21, 1950. This application April 6, 1955, Ser.No. 499,545 p '3 Claims. or. '188234) The present invention relates tobrake shoe construction, and its primary purpose is to provide a brakeshoe having readily separable web and rim elements. The brake shoe isconstructed and arranged to be readily reduceable to the component partswhen servicing is required, albeit such parts are normally firmly heldtogether, or retained in assembly, by reliable holding or locking means.This application is a continuation of my copending application, SerialNo. 145,365, filed February 21, 1950, and now abandoned.

The present invention constitutes an improvement over the inventiondisclosed in the House Patent No. 2,598,545, in that it is simpler inconstruction, easier to produce and consequently less costly, and morereliable in operation. The component parts making up the assembly of thepresent invention can be made by conventional mass production methods tobe interchangeable, thereby providing for ease of original assembly andof replacing worn parts.

The principal differences between the construction of the presentinvention and that of the Hous patent reside in the means for holdingthe shoe in assembled condition and the method for assembling the shoe.The disclosure of the House patent used bar stock to fabricate theholding means, and in production it was found that the close tolerancesrequired impeded production as well as raised the cost of the finishedproduct to a relatively high figure. The present inventionutilizes aconstruction which is easily assembled; lends itself toordinary-manufacturing processes; costs less to produce; and is reliablein operation.

The brake shoe has been developed so that superior shoe assembly methodsmay be utilized. The shoe structure lends itself to an easier, simpler,and more eflicient way of bringing the components together and holdingthem together.

The advantages of a detachable rim shoe can only be realized if the rimand web are easily put together and held together. The two-piece shoemust also lend itself to field replacement and, therefore, theshoe-assembly method must not require costly or elaborate tools.

Other objects and features of the invention will become apparent from aconsideration of the following description which refers to theaccompanying drawings, wherein:

Figure 1 is an exploded view of the component parts of an embodiment ofthe present invention;

Figure 2 is an enlarged side elevation of the resilient leaf spring;

Figure 3 is .a fragmental bottom plan view of one end of an assembledbrake shoe showing the leaf spring in place;

Figure 4 is a side elevation of the same and illustrated in Figure 3;and

Figure 5 is a plan view taken at right angles to Figure 3.

Referring to the drawings, and more particularly to Figure 1, the threeparts are the detachable rim carrying a lining =12, the separatelyformed strengthening web Fee 2 14, and the resilient, or spring element16 used to retain the rim and web in assembled relationship.

The rim 10 has three spaced slots 18, 20, and 22 along its longitudinalcenter line, the slots being provided for the purpose'of receivingcomplementary projections 24, 2'6, and 28, respectively, formed on theweb 14. Referring to the left end of the rim as the fforward end, itwill be observed that the forward, preferably slanted edge of slot 22serves as a surface of engagement 30 and will be engaged by ahook-shaped side 32 on the projection 28.

The i-ear or right, end of the rim 10 is turned inwardly to provide alaterally-extending ledge 34, which serves as a support, or seat, forthe resilient retaining element 16.

The rim 10 and web 14 are separately formed stampings, the web 14 havingan arcuate surface 36 adapted to engage theinner longitudinal centerline of the rim 10. With the rim and web assembled, the hook-shapedsurface 32 prevents relative longitudinal or circumferential movementthereof in one direction while concurrently preventing radial separationof the web from the rim. in assembling the rim and Web, the inclinedsurface 32 also acts to bring the rim and web into tighter radialengagement as the web is urged to the left, or forward end of the rim.

The right end of the web adjacent the ledge 34 is provided with ashallow rectangular shaped notch 38 hava length slightly larger than thewidth dimension of spring element '16. The purpose of this notch 38 isto keep the spring :16 from working out of radial position; however, anymeans for holding the spring in place may be used and in some instances,a part of a brake assembly which lies near the end of ledge 34 mayserve. the purpose.

The other details in the shape of the web are conventional features ofbrake shoes. The invention is, of course, applicable to brake shoes forvarious types of brakes, without limitation to any particularbrakearrangement. The several holes in the illustrated brake web are providedfor such purposes as retaining theends of shoe return springs, locatingshoe holddown devices, and providing a bearing for an anchor link pin.The details of the web shape, except as to the particular featurespreviously noted, are dictated by the requirements of the brake assemblyin which the shoe is to be mounted.

The spring element 16 consists of a semielliptic plate spring fabricatedof spring steel or the like, preferably having a square or rectangularcross section. A locking depression or transverse indentation 40 isformed in the outer side of this spring 16 between its ends to straddlethe thickness of the web 14. While this spring 16 is in assembledposition, this depression 40 straddles the end edge of the web 14therebyholding the spring 16 against endwise or longitudinal movement.With the spring so assembled, it is under a load tending to flatten it,and it, therefore, urges the web and rim into tighter radial engagementthrough the cam action of the hooked-shaped projection 32. While it ispreferred that spring element 16 have a rectangular cross section, it isto be understood that any cross-sectional shaped stock may be used solong as some provision is present in the spring element design to holdit against accidental rotation or movement out of the shoe assembly.

In assembling the shoe, the web is first slipped into position on therim by inserting projection 24 into its slot 18 and then bringing theother projections into their respective slots. The single remaining stepis to assemble the spring element 16. This is accomplished by insertingone end of the spring 16 into the space between the right end of the web14 and the ledge 34, and using a hammer or the like, to force the springlongitudinally product.

into place where the depression '40 straddles the thickness of the web14.

Forcing the spring laterally between the web and rim memberscausesdeflection of the mid portion of the spring, which deflectioncauses loading of the spring.

The spring loading causes relative circumferential movement of the weband rim members, thereby causing them to be brought into intimatecontact by reason of the hook shaped surface 32 on projection 28 at oneend of the shoe.

In disassembling the shoe, a blunt screwdriver blade or the like is usedto drive the spring '16 endwise from its assembled position. from theweb while the brake shoe assembly is mounted in a brake, a suitable toolis inserted into one of the spring holes 42 to withdraw the spring fromthe assembly. This procedure being so simple, it becomes obvious thatthe entire diassembling and reassembling operation can be performed in amatter of a few seconds. 7

With this particular brake shoe design, ordinary manufacturingtolerances are permissible to produce a reliable This conduces toeconomy of manufacture as well as use, since in servicing brakes becauseof worn lining or damaged rims, a factory-lined rim may be substitutedfor the unserviceable one. The cost of the lined rim being relativelylow, the user gets the benefit of lower charges for service labor andlower cost of manufacture.

Although only one embodiment of the invention has been illustrated anddescribed, various changes in the form and relative arrangements of theparts may be made to suit requirements.

I claim:

1. A T-section shoe comprising a rim and web having spaced slots andprojections respectively, said slots removably receiving thereincorresponding projections, one end of said rim being turned inwardly toprovide a flat laterally-extending ledge, at least one of saidprojections having a portion which cooperatively engages a portion ofits slot to cause the web and rim to be brought into tighter engagementas the web is urged toward the end of the rim remote from said ledge,the end of the web adjacent said ledge being notched, and a resilientmemher for holding the web and rim in engagement comprising asemielliptic plate spring element of rectangular cross section, atransverse depression having a width substantially equal to thethickness of the web formed in the outer side of said spring elementbetween the ends thereof, said spring element being inserted between theend of said web and said ledge with the depression straddling said webin the notched portion thereof, said spring element exerting a forcetending to urge the rim If it is vdesired to remove the rimand web inopposite directions whereby the rim and web are brought into tighterengagement.

2. A T-section shoe comprising a rim and web having spaced slots andprojections respectively, said slots removably receiving thereincorresponding projections, one end of said rim being turned inwardly toprovide a flat laterally-extending ledge, at least one of saidprojections having a portion which cooperatively engages a portion ofits slot to cause the web and rim to be brought into tighter engagementas the web is urged toward the end of the rim remote from said ledge,and a resilient member for holding the web and rim in engagementcomprising a plate spring element having a raised center 3.v A brakeshoe comprising a rim, a strengthening webwhich is perpendicular to therim and which detachably engages the inner side of the rim, an inwardlyprojecting ledge formed on one end of said rim, one end, of the webadjacent said ledge being notched, inter-' locking means formed at theother end of said web and rim to hold the web and rim in assembledrelation while they are urged lengthwise one with respect to the other,

and a resilient member for holding the web and rim in engagementcomprising a semielliptic plate spring element of rectangular crosssection, a transverse depres-. sion having a width substantially equalto the thickness of the Web formed in the outer side of said springelement between the ends thereof, said spring element being insertedbetween the end of said web and said ledge with the depressionstraddling said web in the notched portion thereof, said spring elementexerting a force tending to urge the rim and web in opposite directionswhereby the rim and web are brought into tighter en gagement.

References Cited in the file of this patent UNITED STATES PATENTS2,139,409 Hunter Dec. 6, 1938 2,598,545 House May 27, 1952. 2,626,020Keller Jan. 20, 1953 FOREIGN PATENTS 910,765 France Feb. 11, 1946 I

